he is 39-year-old gerardo hernandez. on the job since 2010. transferred recently to los angeles from montana. the first-ever tsa officer killed in the line of duty. >> it's shocking. very nice guy. i'm speechless. i'm shocked. >> reporter: and the shooter, the fbi releasing his picture over night. paul ciancia, a 23-year-old l.a. resident, whom authorities say opened fire with a high-power rifle, inside terminal three early friday morning. >> we have an active shooting in terminal three. >> reporter: witnesses describe a chaotic scene, saying he started shooting right outside the security checkpoint. as police raced in, he made it all the way to the back of the terminal, near the departure gates. passengers ducked for cover. some even hid in a bathroom stall. officers had their guns drawn, yelling at passengers to drop to the floor. >> everybody on the floor. on the floor, now. >> reporter: and after people ran as fast as they could -- >> go, go. >> reporter: the panic and lockdown that followed blocked ambulances from getting close, causing r